Necrotrophic phase of Moniliophthora perniciosa causes salicylic acid accumulation in infected stems of cacao

Moniliophthora perniciosa infects young meristematic tissue of Theobroma cacao and induces abnormal shoot development and ultimately necrosis. We analyzed culture filtrates of M. perniciosa to identify metabolites with possible effects on witches’ broom disease symptom development. All isolates produced salicylic acid (SA), phenyllactic acid and mandelic acid. When SA levels were measured in plant tissues, infected brooms had 5 times more SA compared to healthy shoots. In contrast, leaf inoculation with basidiospores and application of chemical elicitors did not alter leaf SA content. These findings suggest that the necrotrophic phase of M. perniciosa causes SA accumulation in diseased tissues.